Gel permeation chromatography (GPC) is a chromatographic technique that separates molecules based on their relative size in solution. As such, gel permeation and size exclusion chromatography (SEC) are synonymous terms along with gel-filtration chromatography (GFC) and gel chromatography. However, the terms "gel permeation chromatography” or “GPC” are often used by scientists who analyze polymers (plastics or other synthetic polymers) using either organic or aqueous eluents. In some cases, GFC may be used to refer to GPC analysis for aqueous soluble polymers (e.g., polysaccharides, cationic, anionic, and amphoteric polymers). Waters offers GPC/SEC columns for both organic and aqueous polymer separations, and SEC columns for monoclonal antibodies, proteins, peptides, and other biologics.
What can polymer scientists do when using GPC/SEC?
GPC/SEC allows polymer scientists to determine polymer physical properties by characterizing the polymer’s molecular weight distribution. From a molecular weight distribution, a scientist can determine the following parameters which provide information about certain physical properties:
Additionally, scientists can separate a polymer from smaller oligomers, monomers forms, and other formulation additives.
What is the principle of gel permeation chromatography (GPC)?
In GPC analysis, higher molecular weight molecules elute prior to lower molecular weight molecules. This is because the GPC column stationary phase (typically a cross-linked gel) has a defined surface pore size. In a well-designed method, smaller molecules can diffuse more deeply into more pores more often. As a result of spending more time diffusing in and out of pores, smaller molecules elute from the GPC column after larger molecules. Larger molecules are less likely to enter pores and do not spend as much time diffusing in and out pores within the GPC column. Click here for more details.
Waters GPC Columns
For over 50 years, Waters has been the market leader in GPC and SEC analysis, providing the highest quality columns and applications support for both organic- and aqueous-based size separations.
Waters leading GPC/SEC brands include:
Key considerations when selecting the right column for your application:
Designed particularly for low molecular weight samples, the Waters Styragel HR Columns are ideal for the analysis of oligomers, epoxies, polymer additives, phenolics, unsaturated polyester, urea/formaldehyde, polyethylene glycol, ethanolamines, and melamine resin where high resolution is critical. Packed with rigid 5 µm particles, these columns deliver unrivaled resolution and efficiency in the low-to-mid molecular weight range.
The Styragel HT Columns can be used with aggressive solvents at high temperatures without sacrificing resolution or column lifetime. Packed with rigid 10 µm particles, they have a typical plate count greater than 10,000 plates per column. These columns are extremely durable due to a narrow particle size distribution that results in a very stable column bed. Suitable for both ambient- and high-temperature analysis. The Styragel HT Columns offer excellent resolution of polymers in the mid-to-high molecular weight range. Applications include analysis of ABS, acetyl, acrylics, EVA, Nylon, PEEK, and PET/PBT.
The Styragel HMW Columns were specifically designed for the analysis of ultra-high molecular weight polymers susceptible to shearing. Combining high-porosity 10 µm frits and 20 µm particles, the Styragel HMW Columns minimize polymer shear effects. These state-of the-art columns can be used at ambient or elevated temperatures, and exhibit excellent column lifetime. Applications include the analysis of UHDPE, UH-polystyrene, UH-isoprene, and UH-PMMA.
The Envirogel High-Efficiency GPC Cleanup Columns are specifically designed to remove low volatility, high molecular weight interferences, such as lipids and natural resins, from environmental samples as specified in EPA Method 3640A. In the past, the cleanup procedure for environmental samples was performed on low-efficiency GPC columns based on packing particle diameters of 37-75 µm (200 to 400 mesh) Bio-Beads S-Z resins. The high-efficiency Envirogel GPC Cleanup Columns increase the speed of this process while simultaneously reducing solvent consumption.
Shodex Columns are high-efficiency columms for GPC analysis. Featuring a very reproducible styrene and divinylbenzyne technology, these columns have more than thirty years of history and have been used by customers all over the world.
Designed for high-speed GPC analysis, Waters HSPgel Columns provide an accurate and precise determination of molecular weight, increased sample throughput, and greatly reduced solvent consumption and disposal. The HSPgel AQ SEC Columns are optimized for high-speed polymer analysis in aqueous solution at room temperature.
Designed for high-speed GPC analysis, Waters HSPgel Columns provide an accurate and precise determination of molecular weight, increased sample throughput, and greatly reduced solvent consumption and disposal. The HSPgel HR Column series is designed for high resolution, room temperature, organic polymer GPC. They are packed in THF and can be converted once to toluene, methylene chloride, or chloroform. The HSPgel HR Columns are available in 3 µm particle size and are stable from ambient to 80 °C.
Designed for high-speed GPC analysis, Waters HSPgel Columns provide an accurate and precise determination of molecular weight, increased sample throughput, and greatly reduced solvent consumption and disposal. The HSPgel HT Columns are designed for room-temperature to high-temperature (180 °C) organic GPC. The columns are shipped in either THF or ODCB. The ODCB packed column should be used for direct conversion to TCB. These columns can withstand multiple solvent switches.
Designed for high-speed GPC analysis, Waters HSPgel Columns provide an accurate and precise determination of molecular weight, increased sample throughput, and greatly reduced solvent consumption and disposal. The HSPgel RT Columns are designed for room temperature, routine work of organic polymer GPC. They are packed in THF and can be converted multiple times from THF to toluene, chloroform, methylene chloride, DMF, DMSO, etc.
Packed with hydroxylated polymethacrylate-based gel, Waters Ultrahydrogel SEC Columns are ideal for the analysis of aqueous-soluble samples, such as oligomers; oligosaccharides; polysaccharides; and cationic, anionic, and amphoteric polymers. Measuring 7.8 x 300 mm, these high-resolution columns offer many advantages over conventional aqueous SEC columns:
Ultrastyragel Preparative Columns provide high-efficiency GPC separations for compound isolation and sample cleanup. Closely related to Styragel GPC Columns, the family of Ultrastyragel Columns provide a two- to three-fold increase in efficiency (plates/meter) that improves separation speed, and reduces solvent consumption for preparative isolation. Separations that once required several smaller Styragel Columns can be performed on a single, more efficient Ultrastyragel Preparative Column.